Auxiliary digger eou boom-type excavators



Sept. 28 1926.

J. H. McDONALD AUXILIARY DIGGER FOR BOOM TYPE EXCAVATORS Filed June 26; 1922 3 Sheets-Sheet 1 Sept. 28 ,1926. O 1,601,537

J. H. M DONALD AUXILIARY DIGGER FOR BOOM TYPE EXCAVATORS Filed June 26 192 3 Sheets-Sheet 2 Sept. 28,1926. 1,601,537 I J. H. MCDONALD AUXILIARY BIGGER FOR BOOM TYPE EXCAVATORS Filed June 26, 1922 5.5heets-Sheet 5 Slwuentot EEC JASON H. MCDONALD, OF LIMA, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE BUCKEYE TRACTION DITCHER COMPANY, OF FINDLAY, OHIO, A CORPORATION OF OHIO.

Application filed June 26,

This invention relates to excavators and particularly to ditch diggers of the boom type. In machines of this character it is customary to arrange the diggers at spaced intervals on an endless chain-belt, the latter being mounted to travel longitudinally with respect to the boom.

' One disadvantage attending the use of an excavator of this type is that it is limited in its capacity to th digging of a ditch no wider than the width of the digger. Should it be desired to dig ditches of various widths it is ordinarily necessary to keep on hand a plurality of sets of diggers, one set for each width of ditch, and to substitute them for the original diggers on the chain-belt. This represents an expensive investment, and the act of changing the diggers is laborious and time consuming.

The present invention has for its principal object the provision of a digging attachment for auxiliary use with the chain belt type of digger, the same being constructed to adjustably vary the width of the ditch dug by the excavator.

Another object of the invention is the profvision of an auxiliary digger which is removably attachable to the boom of the excavator without interference with the functioning of the main digger, said auxiliary digger being positioned at the side of the main digger and arranged to cut by a move 7 ment transverse to that of the main digger,

and being adjustable so as to accomplish, in co-ordination with the main digger," the digging of ditches of any width within the limits of capacity of the excavator.

Still another object of the invention is the provision of an auxiliary digger consisting of a pair of digger-carrying shafts arranged longitudinally of the boom, one on each side thereof, and detachably secured thereto, said shafts being driven from a jack shaft, itself driven from theoperating gear of the main digger, there being means for 'adjustably varying the space between said digger-carrying shafts and compensating means for maintaining said shafts and the jack shaft in operative engagement throughout all positions of adjustment of the digger-carrying shafts. Also with some makes or designs of machines it will be nec- AUXILIARY BIGGER FOR BOOM-TYPE EXCAVATORS.

1922. Serial No. 570,816.

described in the following specification, and

particularly claimed, and in such variations and ,HlOCllllCfitlOIlS thereof as will be obvious to those skilled in the art to which my invention relates.

In the drawings accompanying and forming a part of this specification, and wherein the preferred embodiment of .my invention is illustrated:

Figure 1 is a side elevation of a boom showing the main digger and the auxiliary digger in place, a portion of the supporting frame being shown in broken lines.

Figure 2 is a plan view of the device shown in Figure 1, with the main digger removed.

Figure 3 is a section taken along the line 33 of Figure 1, the main digger being removed.

Figure 4 is a plan view, partly in sect-ion, showing the compensating drive means for the auxiliary digger.

Figures 5 and 6 are, respectively, an end elevation and a side elevation of a portion of one of the auxiliary digging drums.

Figure 7 is a side elevation of the sprocket which is secured to the jack shaft.

Figure 8 is an end view of the hub by means of which the sprocket is secured to the jack shaft.

Figure 9 is a view of a boom showing a modified form of the invent-ion.

Figure 10 is a cross section taken along the line 1010 of Figure 9.

Figure 11 is a side elevation of one of the telescopic brackets.

Figure 12 is a cross section taken along the'line 12-4-2 of Figure 11.

Referring now in detail to the several figures, the numeral 1 represents the boom which is typical of any one of a number of commercially practicable excavators of the boom type, said boom being adapted for elevation or depression around an axis 2 by means operated by the excavator and not shown, being no part of the present inven tion. A portion of the frame of the excavator to which the boom is attached is indicated in broken lines in Figure 1 and in full lines in Figure 2. The boom which may have any form or design of construction, is here shown as composed of a pair of side plates 3, shown in Figure 3, secured to longitudinally arranged angle members 4: and latticed by means of the diagonal members 5 shown in Figure 2. At its lower and up per ends, respectively, the boom is provided with bearings 6 and 7 in which the shafts 8 and 9 are respectively journalled. Each of these shafts carries a pair of equally spaced sprocket wheels 11 and 12 over which passes the endless chain-belt 13 carrying the diggers 14. The chain-belt is operated through the shaft 9 by means of the gear wheels 15 which are connected to operating means, not shown, carried by the excavator. The chain-belt 13 and diggers 14 will hereinafter be collectively referred to as the 1 main digger to distinguish them from the auxiliary digging device which is included in the subject matter of this invention. When the boom is depressed toward the ground the main digger excavates a ditch the depth of which is determined by the Width of the .dig ers 14.

It frequently desirable to vary the width of the ditch, to which end it has heretofore been necessary in a device, such as has here been described, to remove the chainbelt. 13 and replace it with another chainbelt having wider digging elements attached thereto, or to replace the individual diggers on the chain-belt with those of wider sir: Since each width of digger can dig but one width of ditch, it has been found necessary, in order to adapt the boom type digger to a wide range of work, to keep on hand a plurality of chain-belts provided with diggers of different width. This requires the investment of quite a sum of money and the change from one set of diggers to another is a laborious undertaking which in practice has been found to consume at least half a days time.

In order to obviate this drawback I have invented the auxiliary digger now to be described which comprises a pair of shafts 16 and 17 arranged longitudnally of the boom and journalled in bearings 18 carried by brackets 19, best shown in Figure. 3. Said brackets are arranged at spaced intervals along said shafts and between each pair 'of brackets is mounted a drum 20 carrying the digger teeth 21. Each of the drums 20 comprises a plurality of spiders 22 each including a hub 23 which is keyed to the. shaft, as shown at 24, inFigure 5. The teeth are circular in curvature for a portion of their length as shown at 25, but flare tangentially at their cutting points so as to project beyond the circular periphery of the drum 20. The spiders 22 are connected by longitudinal members 26 to which the teeth 21 are detachably fixed by means of bolts 27 having heads 28 seated within counter-sunk depressions 29 in the outer faces of the teeth and held to the members 26 by means of the nuts 30.

The brackets 19 are suspended from I- beams 31 which are placed across the upper side of the boom 1 and beneath the chainbelt 13 and detachably secured to the I-beams 31 by means of the hook bolts 32 which extend through apertures in the flanges of said I -beams and engage openings 33 drilled in the side plates, 3 of the boom. The hook bolts 32 are tightened by means of the. nuts 33. While the hook bolts 32 are adapted to a boom constructed after the fashion of the one shown in the present drawings said hook bolts, in themselves, form no material part of the invention, and any other securing means may be adopted in place thereof as are best suited to the construction of the boom with which the auxiliary digger is to be used. The lower flanges 34 of the I- beams are provided with a plurality of apertures 35 near their outer ends by means of which the brackets 1-9 may be adjustably secured to said I-beams in various width positions, so as to adjust the distance apart of the auxiliary diggers, by which the width of the ditch is determined. It is obvious from Figure 2 that some of the brackets may be placed closer to the ends of the I-bea-ms than. others, if desired, so as to secure an oblique disposition of the shafts 16 and 17 relative to the median line through the boom 1.

For driving the shafts 1'6 and 17 beveled gears 36 and 37 are secured "at the upper ends of said shafts, said gears meshing with the beveled gears 38 and 39, respectively, which are carried at the ends of a jack shaft 40. Secured at the middlev of the jack shaft 40 is the hub v41, shown in Figure 8, said hub being formed with a flange 48 and hava ing another flange 49 loosely mounted there on and. secured to the flange 48 in clamping relation thereto by the shear bolts 50. A

driving sprocket 51 shown in Figure 7, is positioned between said flanges, the shear bolts passing through apertures in said sprocket. hen the auxiliary digger comes into contact with an immovable object, such as an embedded rock, the shear bolts are designed to break, severing. "the driving connection between the jack shaft and the sprocket and safeguarding the mechanism of the excavator and of the auxiliary digger from damage. VV-henbreakage of the shear bolts 50 occurs it is only necessary, in order to render the auxiliary digger again operative, to renew the shear bolts. The shaft 9 is provided with a sprocket 42, similar to the sprocket 41, a chain 43 passing over said sprockets and affording a driving connection between the shaft .9 and said jack shaft. The pairs of gears 36 and 38 and 37 and 39 are each maintained permanently in mesh by being confined within. bearings in a bracket 44, best shown in Figure i, said bracket comprising bifurcated arms 52 and 53 supporting the aligned bearings 54 and 55 through which passes one of the shafts 16 and 17, the bearings in which the gears 38 and 39 are journalled being arranged at right angles to the aligned bearings 54 and 55, and being constructed with flat faces 45 and 46 against which the respective gears normally abut. In order to permit adjustment of the shafts 16 and 17 laterally of the boom 1, the jack shaft 40 is provided with a hollow bore extending inwardly from each end thereof a distance equal to the maximum lateral displacement of one of the digger-carrying shafts 16 or 17. Said bore is made polygonal in cross section and slidably houses a polygonal stub shaft 47, fitting therein and rotating therewith. Nhen the shafts 16 and 17 are relatively separated in the act of laterally adjusting the same the stub shafts 4-7 are automatically pulled out a compensating distance by means of the brackets 44.

Figures 9 to 12 show a modified form of the invention wherein the I-beams 31 are dispensed with, and telescopic brackets 56 take the place of the laterally adjustable brackets 19 as a supporting means for the shafts 16 and 17 of the auxiliary digger. These brackets 56 consist of channel castings 57, shown in Figures 11 and 12, which are bolted to the opposite sides of the boom, as shown in Figure 10, and each consisting of an outwardly extending socket or well 58 having enlarged cylindrical bores 59 and 60 in its upper and lower ends connected by a reduced flat recess 61. A sliding member 62 is arranged to operate telescopically in these bores and recess, said sliding member including enlarged cylindrical members 63 and 64- connected by a thinner web 65. A slot 66 is formed in a side wall of the socket 58 through which extends a stud 67 threadedly engaging a hole in the web 65. A nut 68 screws upon the outer end of the stud and binds against the wall of the socket 58 in order to hold the sliding member 62 fixed in any position of extension. The

outer face of said sliding member is proided with the half-bearing 69 and cooperates with the bearing cap 70 which is bolted to the face of said sliding member and provided with a half-bearing 71 registering with the half-bearing 69 to form a complete bearing aperture.

In this embodiment of the invention the drums 20 are dispensed with and individual rooters 72 substituted therefor, each of said rooters comprising a hub portion fixedly secured to one of the shafts 16 or 17 and having radial extensions 73 and 74: extending oppositely therefrom and being provided with off-set blades or cutters 7 5 and 76.

While I have above described what I have found to be very practical embodiments of my invention, it is nevertheless to be understood that the auxiliary diggers for boom type excavators may also be exemplified in numerous other alternative constructions and I accordingly reserve the right of adopting all such legitimate changes as may be fairly embodied within the spirit and scope of the invention as claimed.

Having described my invention what I claim as new and desire to secure by Letters Patent, is

1. In combination with a boom-type excavator having a main digger operating by movement in a direction longitudinally of the boo-m, and means for driving said main digger, an auxiliary digger arranged laterally of the main digger and movable in a plane transversely of the plane of movement of the main digger, said auxiliary digger being laterally adjustable with respect to the main digger, means for driving the auxiliary digger from the main digger operating means, said means being constructed to compensate for the lateral adjustment of the auxiliary digger.

2. In combination with a boom-type excavator having a main digger operating by movement in a direction longitudinally of the boom, and means for driving said main digger, an auxiliary digger arranged laterally of the main digger comprising a shaft having digger elements attached thereto, said shaft being rotatable in a plane transversely of the plane of movement of the main digger, and laterally adjustable with respect to said main digger, a gear on said shaft, a jack shaft provided with a gear meshing with the gear on said digger-carry ing shaft, said ack shaft being driven from the main digger operating means, and being constructed to compensate for the lateral adjustment of said digger-carrying shaft.

3. In combination with a boom-type excavator having a main digger operable by movement in a direction longitudinally of the boom, and means for driving said main digger, an auxiliary digger arranged laterally of the main digger comprising a shaft, digger elements carried by said shaft and rotatable in a plane transversely of the plane of movement of the main digger, said shaft being laterally adjustable with respect to the main digger, a jack shaft, means for driving said jack shaft from the main digger operating means, said jack shaft being constructed with a telescopic end portion, intermeshing bevel gears on the adjacent ends respectively of said digger carrying shaft and jack shaft, means for maintaining said gears in mesh, the telescopic portion of said jack shaft functioning to compensate for lateral adjustment of the digger-carrying shaft.

4. In combination with a boom-type excavator having a main digger operable by movement in a direction longitudinally of the boom and means for driving said main digger, an auxiliary digger arranged laterally of the main digger comprising a shaft, digger elements carried by said shaft and rotatabledn a plane transversely of the plane of movement of the main digger, said auxiliary digger being laterally adjustable with respect to the main digger, a jack shaft driven from said main digger driving means, said jack shaft being provided at its end with a polygonal bore, a polygonal stubshaft slidably fitting within said bore to r.o tate with said ack shaft, intermeshing gears on the end s of said digger carrying shaft and stub-shaft respectively, a bracket provided with angularly disposed bearings encircling said digger-carrying shaft and stub-shaftedj acent said gears and affording means for retaining them in mesh, said stub-shaft being automatically extended from said ask shaft upon lateral adjustment of the digger carrying shaft. I

5; In combination with a boom-type e2;- cavator having a main digger operable by movement in a direction longitudinally of the boom and means for driving said main digger, an auxiliary digger comprising a shaft arranged laterally of themain digger, digger elements carried by said shaft rotatable in a plane transversely of the plane of movement ofthe main digger, brackets supported by the boom and carrying bearings in which said shaft is journalled and means for laterally adjusting the position of said brackets.

6. In combination with a boom-type exca vator having a main digger operable by movement in a direction longitudinally of the boom and means for driving said main digger, an auxiliary digger comprising a shaft arranged laterally of the main digger,

, digger means carried by said shaft rotatable in a plane transversely of the )lane of movement of the main digger, braclcet supporting members,v means for detachably securing said bracket supporting members to said boom, brackets carried by said supporting members,

' said brackets being provided with bearings in which said shaft is journalled and means for laterally adjusting the position of said brackets upon said bracket supporting members.

7. In combination with a boom-type excavator having a main digger operable by movement in a direction longitudinally of the boom, a means for driving said main digger, an auxiliary digger comprising a shaft is journalled and means for adjustably securing said brackets in any position of extension.

1 8. In a machine of the class described, a boom, trench side cutting means carried by the boom at a side thereof and rotatable about an axis disposed lengthwise of the boom, and means for driving the cutting means. I

9. In a machine of the class described, a boom, a shaft mounted at each side of the boom longitudinally thereof for inward and outward adjustment relative thereto, rotary cutters carried by each shaft, and means for driving the shafts in any position of adjustment thereof 1.0. In a machine of the class described, a boom, an endless bnclret chain carried by the boom, a shaft carried by the boom at a side thereof and disposed longitudinally of the boom, rotary cutters carried by the shaft, and means for driving the bucket chain and shaft in unison.

11. In a machine of the class described, a boom, a bucket chain carried by the boom, a shaft disposed at a side of the boom longitudinally thereof, bearings for the shaft projecting from the boom and having relatively slidable parts for permitting an inward and outward adjustment of the shaft with rcspec to the boom, rotary cutters on the shaft, and means for driving the bucket chain and shaft in unison and having adjustable connection with the shaft.

12. In a machine of the class described, a boom, a shaft mounted at a side of the boom longitudinally thereof for inward and outward adjustment relative thereto, rotary cutters carried by the shaft, a crossshaft jour naled in the boom, a shaft in driven connection with the cross-shaft and axially adjustable with respect thereto, said driven shaft having driving connection With the cutter shaft, and means for driving the cross shaft.

13. In a machine of the class described, a

boom, a shaft mounted at each side of the boom longitudinally thereof for inward and outward adjustment relative thereto, rotary cutters carried by each shaft, a hollow cross shaft journaled in the boom, shaft sections 7 telescoped with the cross shaft for axial adjustment relative thereto and in driving connection therewith, driving connection between the shaft sections and cutter shafts,

and means operable to drive the hollow sides of said mechanism, cutters on said shafts, said shaft-s being adjustable toward or from said mechanism.

15. In an excavator, a boom, a main digger carried thereby, means for driving said main digger, .a shaft extending transversely of said boom and driven by "said driving means, an auxiliary digger including a shaft arranged longitudinally with respect to said boom and rotatable upon an axis perpendicular to the axis of rotation of said transverse shaft, means for adjustably varying the distance of said longitudinal shaft from said boom, intermeshing gears carried by adjacent ends of said transverse and longitudinal shafts, and a bracket carried by said longitudinal shaft, said bracket being provided with bearings having a fixed relation, in which said shafts are journalled for maintaining the perpendicular relation of the axes of said intermeshing gears throughout the range of adjustment of said longitudinal shafts.

16. In an excavator, a boom, a main digger carried thereby, means for driving said main digger, a shaft extending transversely of said boom and driven by said driving means, an auxiliary digger including a shaft arranged longitudinally with respect to said boom and rotatable upon an axis perpendicular to the axis of rotation of said transverse shaft, intermeshing gears carried by adjacent ends of said transverse and longitudinal shafts, means for adjustably varying the distance of said longitudinal shaft from said boom, including telescopic members, one secured to said boom and the other affording a bearing for said shaft, and means for securing said members in various positions of relative extension.

17. In a trench excavating machine, a boom, a main excavating means carried by the boom, a trench side-cutting means carried by the boom at a side thereof with respect to the direction of movement of the main excavating means lengthwise of the trench being dug, said side-cutting means being rotatable about an axis disposed lengthwise of the boom, and means for driving the main and side-cutting means.

18. In a trench excavating machine, 3a boom, a main excavating means carried by the boom, a trench side-cutting means carried by the boom at a side thereof with respect to the direction of movement of the main excavating means lengthwise of the trench being dug, said side-cutting means being rotatable about an axis disposed lengthwise of the boom, and means for driving the ma n and side-cutting means, said side-cutting means including cutters on both sides of the boom.

19. In a trench excavating machine, a frame movable lengthwise of a trench being dug, a boom adapted to project from the frame into the trench, main excavating means carried by the boom, a shaft carried by the boom at a side thereof, and of the excavating means relative to a digging movement thereof and having cutters rotatable therewith for acting on a side wall of the trench being dug, said shaft being disposed lengthwise of the boom and carried entirely thereby for movements therewith, and means for driving the ma n excavating means and shaft.

20. In a trench excavating machine movable lengthwise of a trench being dug, a boom adapted to be projected into a trench lengthwise thereof, a main excavating means carried by the boom, rotary shafts carried by the boom at opposite sides of said means and disposed lengthwise of the boom, cutters on each of said shafts for simultaneously operating on opposite sides of the trench being dug, and means for driving the excavating means and shafts.

21. In a trench excavating machine movable lengthwise of a trench being dug, a boom adapted to be projected into a trench lengthwise thereof, a main excavating means carried by the boom, rotary shafts carried by the boom at opposite sides of said means and disposed lengthwise of the boom, cutters on each of said shafts for simultaneously operating on opposite sides of the trench being dug, and means for driving the excavating means and shafts, said shafts being adjustable with respect to the boom to suit the width of the trench and slope of the trench walls desired.

In testimony whereof I have hereunto set my hand.

JASON H. MCDONALD. 

